[Dynamic research of density on Platycodon grandiflorum dry material accumulation and platycodin D content in Platycodon grandiflorum].

OBJECTIVE: To study the dynamic changes of dry material accumulation and platycodin D content in Platycodon grandiflorum in different planting densities. METHOD: Five different planting densities M1 (4 cm x 25 cm), M2 (6 cm x 25 cm), M3 (8 cm x 25 cm), M4 (10 cm x 25 cm) and M5 (12 cm x 25 cm) were designed in the plot experiment. The individual and colony biomass accumulation, dry material distribution, root yield and platycodin D content were measured in different stage. RESULT: In a certain density range the individual biomass in P. grandiflorum obviously declined with increasing density with the exception of biomass M2 > biomass M3. On the contrary, the colony biomass increased with the increasing density. Dry material accumulation in each organ in P. grandiflorum in different planting densities showed significance (P<0.05). The dry material distribution in organs in the different planting densities showed significance (P<0.05), and the dry material distribution in flower and fruit reached the minimal level in M2, in the same planting density the distribution in root reached the maximal; The dry material in stem, flower and fruit obviously declined with the increasing density, while the dry material in leaf increased. The individual root output increased with the increasing density, and it reached the highest in M2. The colony root yield increased with the increasing density. The platycodin D content in P. grandiflorum reached the highest in M2. CONCLUSION: The result showed that a suitable planting density is very important to P. grandiflorum dry material accumulation and distribution, root yield, platycodin D content and colony yield.

[Relationship between photosynthetic characteristics and environmental factors in leaves of Pueraria lobata].

OBJECTIVE: To study the relationship between photosynthetic characteristics and environmental factors in leaves of P. lobata. METHOD: Photosynthetic characteristics and environmental factors were measured by using CIRAS-2 portable photosynthesis system. RESULT: The apparent quantum yield in leaves was 0.0173 micromol CO2 x micromol(-1) photon. The dark respiration rate was 2.9333 micromol x m(-2) x s(-1). The light compensation point of photosynthesis was 180 micromol x m(-2) x s(-1). The light saturation point was 1600 micromol x m(-2) x s(-1). The carboxylation efficiency was 0.0338 micromol x m(-2) x s(-1). The light respiration rate was 2.5 micromol x m(-2) x s(-1). The CO2 compensation point was 100 micromol x mol(-1), The CO2 saturation point was 1 600 micromol x mol(-1). CONCLUSION: Photo flux density and air temperature are major environmental factors influencing diumal changes of net photosynthetic rate.

[Observation of pollen tube germination of Platycodon grandiflorum by fluorescence microscopy].

OBJECTIVE: To determine the self-compatibility of Platycodon grandiflorum and the location of microspore germination on stigma. METHOD: The microspore germination of self-pollination, self-plant-pollination and cross-pollination and the pollination microspore germination in and outside of stigma were observed with fluorescence microscopy. RESULT: Most pollens of self-pollination, self-plant-pollination and cross-pollination can germinate on the stigma, and after 24 hours, pollen tube entered into the ovary successfully. Pollinated on the outer-surface of stigma, microspores could not germinate, but on the inner-surface of the stigma when it dehisced most microspores can germinate. CONCLUSION: The compatibility of self-plant-pollination of Platycodon grandiflorum is high. The microspore germination loci is on the inner-surface of the dehisced stigma.

[Advances in research on pharmacodynamics and chemical conversion of catalpol].

Catalpol is a active component in Rehmannia Root, and its pharmacological effects are extensive. In this paper its effects and chemical changes were summarized. This will offer the reference for further research work catalpol.

[Study on seed quality test and quality standard of Platycodon grandiflorum].

OBJECTIVE: To study quality test, and establish quality classification standard of Platycodon grandiflorum. METHOD: The seed quality and planting quality of P. grandiflorum from different producing areas and in different growing years were measured. RESULT AND CONCLUSION: The range of seed purity, weight per 1000 seeds, seed moisture content,seed viability were determined and the primary seed quality classification standard was established.